• Journal of Technologic Dentistry
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• v.37 no.4
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• pp.229-234
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• 2015

Purpose: The purpose of this study was to analysis the internal fitness of single crown fabricated by additive method technique. Methods: Study models were fabricated. Ten crowns were manufactured by additive method technique (AM group) and another ten crowns using conventional method were manufactured (CM group). The internal fitness of specimens were measured using silicone replica technique. Silicone replicas were sectioned one times (direction: from mesial to distal). The internal fitness were evaluated using by digital microscope. Statistical analyses were performed with independent samples t-test. (${\alpha}=0.05$). Results: Mean(SD) of all internal fitness were $92.1(20.0){\mu}m$ for AM group and $69.7(12.3){\mu}m$ for CM group. Two groups were statistically significant differences (p<0.001). Conclusion: All internal gaps of AM group were ranged within the clinical recommendation ($120{\ss}{\neq}$).

• Journal of dental hygiene science
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• v.19 no.4
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• pp.238-244
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• 2019

Background: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method. Methods: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups. Results: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP. Conclusion: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

• Journal of Technologic Dentistry
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• v.39 no.1
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• pp.17-24
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• 2017

Purpose: The purpose of this study was to evaluate the internal fitness of the resin coping that was fabricated by the traditional and Digital manufacturing methods through 3-dimensional analysis. Methods: maxillary right second molar was chosen implant master model. Custom-built impression trays were manufactured. After screwing the pick-up impression coping onto the master cast, impressions were made with silicone impression. The Working model was then made with type IV stone. The coping was fabricated: SLAC group (n=8), APPC group (n=8), LAPC group (n=8) Resin coping data was measured by using a three-dimensional evaluation program. Internal fitness was calculated by RMS (Root Mean Square).It measures mean and Standard Deviation (SD). Results: Three groups are measured $47.11{\pm}(3.08){\mu}m$ total RMS of SLAC group, $48.35({\pm}1.55{\mu}m)$ for total RMS of LAPC group, $43.45{\pm}2.09{\mu}m$ for total RMS of APPC group. Measured value is gradually increased. Followed by autopolymerized pattern resin; Stereolithography resin, Light-activated pattern resin But there were no differences stastically(P>0.321). Conclusion: Evaluation of internal fitness on Resin copings was fabricated by three-ways methods showed that no differences statistically significant and clinically acceptable results.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.2
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• pp.135-142
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• 2010

Purpose: This study was aimed to compare the margin and internal fitness of single anterior all-ceramic crown zirconia core made by three deferent CAD/CAM systems. Material and methods: Five single zirconia cores were manufactured by three deferent CAD/CAM systems($Cerasys^{(R)}$system, KaVo $Everest^{(R)}$system, $LAVA^{TM}$system). The manufactured zirconia cores were duplicated through the use of replica technique, and a replicated sample was sectioned in the center of bucolingual and mesiodistal direction to measure the marginal and internal gap. Measurement was carried out by using measuring microscope ($AXIO^{(R)}$) and $I-Solution^{(R)}$ and analysed through the use of ANOVA. Results: As for the mean marginal fitness of the zirconia core, it was $84.74{\pm}27.57{\mu}m$, in $Cerasys^{(R)}$, $80.23{\pm}21.07{\mu}m$ in KaVo $Everest^{(R)}$ and $96.37 {\pm}11.45{\mu}m$ in $LAVA^{TM}$, and as for the mean internal gap, it was $94.11{\pm}30.07{\mu}m$ in $Cerasys^{(R)}$, $92.31{\pm}25.18{\mu}m$ in KaVo $Everest^{(R)}$, and $94.99{\pm}18.74 {\mu}m$ in $LAVA^{TM}$. There was no significant statistically deference among the total average gap of three systems. The internal gap in KaVo $Everest^{(R)}$ seemed to be smaller than $LAVA^{TM}$ (P < .05). The internal gap in the incisal area was larger in all of the three systems. Conclusion: There was no difference in marginal fitness in $Cerasys^{(R)}$, KaVo $Everest^{(R)}$ and $LAVA^{TM}$. As for the internal fitness, it was smaller in KaVo $Everest^{(R)}$ system than $LAVA^{TM}$ system. In all of the three systems, there was a larger gap in incisal area. The marginal and internal gap was within the clinically allowed range in all of the three systems.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.77-89
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• 2008

The purpose of this study was to evaluate internal conical abutment sinking and fitness according to the loading condition. In this study, Alloden implant fixture and two abutment(conventional, FDI) systems were used. Each abutment was applied 1 time of finger force, 3 times of malleting force, 5 times of 20kg and extra several times to the fixture until the amount of abutment singking showed no change. Then, the length of abutment to fixture which was binding lightly with no pressure state was measured by Vernier caliper. After loading application, the length was remeasured and the amount of sinking was calculated. The implant was buried in unsaturated polyester (Epovia, Cray Valley Inc. Korea) for making a comparison between the change of length and fitness of abutment-fixture connection part. Then All samples were cross-sectioned with high speed precision cut-off(accutom-5, Struers, Denmark). Finally, The result were observed and analyzed using FE-SEM (field emission scanning electron microscopy).

• Journal of Technology Innovation
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• v.21 no.2
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• pp.285-317
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• 2013

This paper delineates dynamic capabilities, which can be measured by internal capability and external knowledge, and also, in the shape of dynamic capabilities, bases on that corporate actions are expatiated by fitness and rent of evolutionary perspective. To achieve the goal of this study, classifying types of Nano-technology enterprise and suggesting analytical pattern based on dynamic capabilities, this thesis substantially analyzes how to categorize a type of enterprise and gauge a result through a survey of 359 domestic companies producing goods concerned with Nano-technology. This paper analyzes whether or not the internal capability and external knowledge affect the outcome of a certain enterprise. Moreover, in according to the results of practical analysis, it deducts 2 new variables by applying principal component analysis on four previous variables showing the internal capability and external knowledge. By classifying four types of enterprises with criterion of these two factors based on a relative extent and comparing each typical financial result, this paper suggests that the companies with relatively higher level of the internal capability and external knowledge surpass the lower ones at the financial outcome. Not only this, but also the technology-level analysis shows the same result, the higher capability and knowledge the higher performance. However, the analysis based on the difference of the four types of financial outcomes reveals that technological and evolutionary fitness can determine financial achievement.

• The Journal of Society for e-Business Studies
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• v.8 no.4
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• pp.1-16
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• 2003

ERP implementations are known to be unusually difficult, even when compared to other large-scale systems developing in a firm level, because it requires a substantial investment of time, money, and internal resources. Moreover, medium and small-sized enterprises that are increasingly adopting ERP feel much difficult due to the lack of resources. To promote the spread of ERP in medium and small-sized enterprises, "ERP template standardization methodology" led by government has been used for constructing ERP system in Korea. In this study, we present a study to measure fitness between ERP standard templates and business processes of 10 small enterprises in 5 industries. Also, we define a fitness measure suitable for this purpose. We car find that ERP template standardization methodology is partly adequate to establish ERP systems and it is required to add to templates which support the differences of business process.

• Journal of muscle and joint health
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• v.19 no.2
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• pp.210-222
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• 2012

Purpose: This study examined the effects of taekwondo exercise program on the physical function, fitness and quality of life in women with osteoarthritis. Methods: With nonequivalent control group quasi-experimental design, 17 outpatients with osteoarthritis were recruited from June to August, 2010. The subjects were divided into 14 in experimental group and 13 in control group. The taekwondo exercise program was consisted of public taekwondo gymnastics with stretching movement and carried out every 60 minutes, 2 times a week for 12 weeks. Physical fitness of sit up, sit and reach, and agility, KWOMAC, and quality of life were measured. Data were analyzed by t-test and Mann-Whitney test using SPSS program. Results: After the intervention, the physical fitness for muscle endurance (Z=-4.40, p<.001), flexibility (Z=-2.75, p=.006), and agility (Z=-1.95, p=.050) were significantly improved in the experimental group. The mean scores of KWOMAC in the experimental group were significantly decreased (Z=-2.94, p=.003) and the mean difference of quality of life in the experimental group was also significantly increased than that of the control group (Z=-3.50, p<.001). Conclusion: The taekwondo exercise program may have affirmative effects on physical fitness, physical function, and quality of life in women with osteoarthritis.

• Journal of Technologic Dentistry
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• v.41 no.4
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• pp.263-269
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• 2019

Purpose: The purpose of this study was to evaluate the internal fitness of prostheses fabricated with non-contact extra-oral scanner and those fabricated with intra-oral video scanner, with a comparative accuracy analyses of their precision and trueness. Methods: A polymethyl methacrylate (PMMA) model was fabricated by replicating a master model. The prostheses in the first group were fabricated based on the PMMA model with an intra-oral video scanner (IVS group). Following the fabrication of work models with Type IV Stone that were based on the PMMA model, the prostheses in the second group were fabricated with a non-contact extra-oral scanner (ENB group). The precision and trueness of the prostheses were calculated from comparisons of the three-dimensional images of the internal surfaces of the prostheses and those of the master model. Kruskal-Wallis tests were used to determine the statistical significance, with the level of type 1 error set at 0.05. Results: Trueness (P < 0.009) and precision (P < 0.001) did not differ significantly between the ENB and IVS groups. The IVS group exhibited lower trueness values and larger precision values than the ENB group. Conclusion: Although no significant differences were found in the internal fitness of the prostheses that were fabricated by the two different scanners, the intraoral video scanner-fabricated prostheses had better trueness, whereas the non-contact extra-oral scanner-fabricated prostheses had better precision.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.236-244
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• 2011

Purpose: This study was aimed to compare the margin and internal fitness of 3-unit zirconia bridge cores fabricated by several CAD/CAM systems using replica technique. Materials and methods: Three unit-bridge models in which upper canine and upper second premolar were used as abutments and upper first premolar was missed, were fabricated. Fourty models were classified into 4 groups (Cerasys$^{(R)}$ (Group C), Dentaim$^{(R)}$ (Group D), KaVo Everest$^{(R)}$ (Group K), $Lava^{TM}$ (Group L)), and zirconia cores were fabricated by each company. Sixteen points were measured on each abutment by replica technique. Statistical analysis was accomplished with two way ANOVA and Dunnett T3 (${\alpha}$=.05). Results: In most systems, there was a larger gap on inter margin than outer margin. In the Group K, overall fitness was excellent, but the incisal gap was very large. In the Group C, marginal gap was significantly larger than Group K, but overall internal gap was uniform (P<.05). The axial gap was under $100\;{\mu}m$ in all system. The difference between internal and external gap was small on Group L and C. However, internal gap was significantly larger than external gap in Group D (P<.05). The fitness of canine was better than second premolar among abutments (P<.05). Conclusion: The marginal and internal gap was within the clinically allowed range in all of the three systems. There was a larger gap on second premolar than canine on internal and marginal surface. In most systems, there was a larger gap on occlusal surface than axial surface.